【Objective】 To analyze the effect of extensively hydrolyzed formula(eHF) in the treatment of feeding intolerance in preterm infants and the effect on hospital infection, in order to provide reference for the clinical treatment of feeding intolerance in preterm infants. 【Methods】 A total of 208 cases of preterm infants with feeding intolerance diagnosed and treated in Shandong Heze Municipal Hospital from April 2017 to February 2020 were selected into the clinical trial for eligibility assessment, then were randomly assigned into study group(n=100) and control group(n=100) after screening and exclusion. Children in the control group were fed with standard preterm formula, while children in the study group were fed with eHF. Feeding tolerance indicators, including daily milk intake, time to meconium evacuation, time to full gastrointestinal nutrition, total gastric residual counts(GRV1) in the 7-d period after resumption of breastfeeding, ratio of all-day gastric residual counts/all-day estimated milk intake after resumption of breastfeeding(GRV2) were compared between the two groups, and growth indicators(body weight growth rate, head dimension growth rate), complication incidence [necrotizing enterocolitis(NEC), pathological jaundice, positive fecal occult blood or blood in stool] and incidence of hospital-acquired infections. 【Results】 The daily milk intake(t=5.037) of the study group was higher than that of the control group, and the time of foetal excretion(t=9.217), the time to reach full gastrointestinal nutrition(t=15.833), GRV1(t=6.737), GRV2(t=9.956) were lower than those of the control group, and the differences were all statistically significant(P<0.05). The rate of weight gain(t=2.454) and head dimension growth(t=5.469) in the study group was significantly higher than those of the control group(P<0.05). The incidence of the three complications of NEC, pathological jaundice and positive fecal occult blood or blood in stool(χ²=4.310) and the incidence of hospital infections(χ²=4.688) were significantly lower in the study group than in the control group(P<0.05). 【Conclusions】 Compared with the standard formula milk for preterm infants, eHF can significantly improve the feeding intolerance of preterm infants, promote growth and development, and reduce the occurrence of hospital-acquired infections. Therefore, eHF can be widely used in clinic for preterm infants with feeding intolerance.